Ureteral reconstruction: small intestine submucosa for the management of strictures and defects of the upper third of the ureter

PURPOSE: We evaluated the effectiveness of small intestine submucosa in ureteral reconstruction. MATERIALS AND METHODS: We report an experimental study in 6 female pigs weighing between 50 and 60 pounds. The animals were anesthetized, midline laparotomy was performed and two-thirds of the diameter of the upper third of the left ureter were incised parallel to the ureteral axis, leaving intact only a third of the ureteral wall for a segment of 7 cm. A 5Fr double-J*; stent was positioned to secure patency at all times. The created gap was then bridged with an small intestine submucosa patch in a cylindrical format, which was subsequently sutured to the proximal and distal ureteral segment. The right ureter served as our control and simple intubated Davis ureterotomy was performed. RESULTS: All animals survived the whole followup of 7 weeks. Histologically there was evidence of epithelial regeneration along the segments reconstructed with small intestine submucosa, supported by a well vascularized collagen and smooth muscle background. There was no evidence of foreign body reaction to the graft material. In vivo patency was confirmed by retrograde pyelography in the bridged ureters 7 weeks after the initial procedure. All the ureters without an small intestine submucosa bridge had ureteral stenosis without evidence of epithelial regeneration. CONCLUSIONS: The use of small intestine submucosa is a novel, effective material for the scaffolding of ureteral defects and/or strictures of the upper ureteral segment in the pig model.